Packet-based communication systems allow the user of a device, such as a personal computer, to communicate across the computer network using a packet protocol such as Internet Protocol (IP). Packet-based communication systems can be used for various types of communication events. Communication events which can be established include voice calls, video calls, instant messaging, voice mail, file transfer and others. These systems are beneficial to the user as they are often of significantly lower cost than fixed line or mobile networks. This may particularly be the case for long-distance communication. To use a packet-based system, the user installs and executes client software on their device. The client software provides the packet-based connections as well as other functions such as registration and authentication.
Communications systems allow users of devices to communicate across a computer network such as the internet. Communication events which can be established include voice calls, video calls, instant messaging, voice mail, file transfer and others. With video calling, the callers are able to view video images of the other party in addition to voice information. This enables a much more natural communication between the parties, as facial expressions are also communicated, thereby making video calls more comparable to a face-to-face conversation.
It is known for a communication client application to provide functionality to enable a user to modify video captured at the user's device by adding two-dimensional clip-art effects. For example a user may select to add a moustache effect, the application detects the position of a user's face in a captured frame and overlays the moustache effect at a position in the frame in dependence on the position of the user's face in the captured frame. Thus the moustache moves two-dimensionally as the user's face changes position in the captured video.